The Taleban in Afghanistan says it has agreed to hold direct talks with a top South Korean official about the release of 21 South Korean hostages.

The two sides are still deciding on a location for the negotiations.

South Korea and the United States say they have ruled out using force to free the remaining hostages. A South Korean presidential spokesman, Cheon Ho-seon, says any rescue attempt would require South Korean permission.

A delegation of South Korean lawmakers is traveling to the United States to persuade Washington to help end the standoff.

The Taleban says the hostages are still alive - but warns that any rescue operation would jeopardize the their lives.

On Wednesday, Afghan officials dropped leaflets warning of a possible military operation in Ghazni, where the hostages are thought to be held. But they said the leaflets referred to a routine operation not related to the hostage crisis.

The kidnappers already have killed two male hostages. They are demanding that the Afghan government free Taleban prisoners in exchange for the captives.

The government in Kabul says it will not release Taleban prisoners for hostages.

Twenty-three South Korean Christian volunteers were abducted July 19 while traveling by bus to southern Kandahar province, a Taleban stronghold.